Drug Fixes Cellular Defects in Autism Disorder
A new stem-cell model of Phelan-McDermid syndrome points to a possible treatment for the rare autism-related disorder, according to a study published 16 October in Nature.
Phelan-McDermid syndrome is characterized by intellectual disability, autism, seizures, sleep trouble and motor problems. It is caused by glitches in the 22q13 chromosomal region, which includes SHANK3, a well-known autism candidate gene.
Several mouse models lacking SHANK3 have shown relatively subtle abnormalities, however. Each of these models has a different set of brain and behavioral defects, which researchers are only beginning to understand.
"We like mice, and we think they provide interesting insights into disease, but at the same time, we know that they are not always really great predictors of the human disease," says Ricardo Dolmetsch, global head of neuroscience at the Novartis Institutes for Biomedical Research in Cambridge, Massachusetts. "In the case of Phelan-McDermid, that's definitely true."
Dolmetsch and his colleagues used chemical soups to turn skin cells from individuals with Phelan-McDermid syndrome into neurons. Compared with controls, these neurons have fewersynapses, or junctions between neurons, and dampened transmission of electrical messages between them, the study found.
When the abnormal cells are exposed to a hormone called insulin-like growth factor 1 (IGF1), however, their synaptic signaling is restored to normal levels.
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